The majority of states already have early voting AND absentee voting. Some states are mail-in only voting. It has not moved the needle as I said.
I don't think that the disengaged care enough to vote regardless of the day or time. And I agree with you that they would be LESS likely to vote on a Saturday.
The only thing I can think of would be internet voting via app or something, the way you do for shareholder meetings but that is rife with problems. First you'd need to get your package with the voter access number in the mail on time (many people move, addresses on file are not updated, voters aren't registered in advance, mail delivery issues), then you'd have to make sure the voting isn't fraudulent, that there is no hacking, double voting, etc. I don't see it as realistic that we're there yet with technology and I also worry that people would see such elections as illegitimate.